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* [PATCH -next] drm: Fix PM reference leak
@ 2021-05-21 13:03 Zou Wei
  2021-05-21 15:32 ` Daniel Vetter
  0 siblings, 1 reply; 3+ messages in thread
From: Zou Wei @ 2021-05-21 13:03 UTC (permalink / raw)
  To: a.hajda, narmstrong, robert.foss, Laurent.pinchart, jonas,
	jernej.skrabec, airlied, daniel, emma, mripard
  Cc: dri-devel, linux-kernel, Zou Wei

pm_runtime_get_sync will increment pm usage counter even it failed.
Forgetting to putting operation will result in reference leak here.
Fix it by replacing it with pm_runtime_resume_and_get to keep usage
counter balanced.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zou Wei <zou_wei@huawei.com>
---
 drivers/gpu/drm/bridge/cdns-dsi.c | 2 +-
 drivers/gpu/drm/vc4/vc4_hdmi.c    | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/bridge/cdns-dsi.c b/drivers/gpu/drm/bridge/cdns-dsi.c
index 76373e3..b31281f 100644
--- a/drivers/gpu/drm/bridge/cdns-dsi.c
+++ b/drivers/gpu/drm/bridge/cdns-dsi.c
@@ -1028,7 +1028,7 @@ static ssize_t cdns_dsi_transfer(struct mipi_dsi_host *host,
 	struct mipi_dsi_packet packet;
 	int ret, i, tx_len, rx_len;
 
-	ret = pm_runtime_get_sync(host->dev);
+	ret = pm_runtime_resume_and_get(host->dev);
 	if (ret < 0)
 		return ret;
 
diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index c27b287..f20a65b 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -798,7 +798,7 @@ static void vc4_hdmi_encoder_pre_crtc_configure(struct drm_encoder *encoder,
 	unsigned long pixel_rate, hsm_rate;
 	int ret;
 
-	ret = pm_runtime_get_sync(&vc4_hdmi->pdev->dev);
+	ret = pm_runtime_resume_and_get(&vc4_hdmi->pdev->dev);
 	if (ret < 0) {
 		DRM_ERROR("Failed to retain power domain: %d\n", ret);
 		return;
-- 
2.6.2


^ permalink raw reply related	[flat|nested] 3+ messages in thread
* Re: [PATCH -next] drm: Fix PM reference leak
  2021-05-21 13:03 [PATCH -next] drm: Fix PM reference leak Zou Wei
@ 2021-05-21 15:32 ` Daniel Vetter
  2021-05-24  6:37   ` Samuel Zou
  0 siblings, 1 reply; 3+ messages in thread
From: Daniel Vetter @ 2021-05-21 15:32 UTC (permalink / raw)
  To: Zou Wei
  Cc: a.hajda, narmstrong, robert.foss, Laurent.pinchart, jonas,
	jernej.skrabec, airlied, daniel, emma, mripard, dri-devel,
	linux-kernel

On Fri, May 21, 2021 at 09:03:06PM +0800, Zou Wei wrote:
> pm_runtime_get_sync will increment pm usage counter even it failed.
> Forgetting to putting operation will result in reference leak here.
> Fix it by replacing it with pm_runtime_resume_and_get to keep usage
> counter balanced.
> 
> Reported-by: Hulk Robot <hulkci@huawei.com>
> Signed-off-by: Zou Wei <zou_wei@huawei.com>

Looks good, but can you pls split this up into a patch per driver (vc and
bridge/cdns-dsi here)?

Thanks, Daniel

> ---
>  drivers/gpu/drm/bridge/cdns-dsi.c | 2 +-
>  drivers/gpu/drm/vc4/vc4_hdmi.c    | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/bridge/cdns-dsi.c b/drivers/gpu/drm/bridge/cdns-dsi.c
> index 76373e3..b31281f 100644
> --- a/drivers/gpu/drm/bridge/cdns-dsi.c
> +++ b/drivers/gpu/drm/bridge/cdns-dsi.c
> @@ -1028,7 +1028,7 @@ static ssize_t cdns_dsi_transfer(struct mipi_dsi_host *host,
>  	struct mipi_dsi_packet packet;
>  	int ret, i, tx_len, rx_len;
>  
> -	ret = pm_runtime_get_sync(host->dev);
> +	ret = pm_runtime_resume_and_get(host->dev);
>  	if (ret < 0)
>  		return ret;
>  
> diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
> index c27b287..f20a65b 100644
> --- a/drivers/gpu/drm/vc4/vc4_hdmi.c
> +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
> @@ -798,7 +798,7 @@ static void vc4_hdmi_encoder_pre_crtc_configure(struct drm_encoder *encoder,
>  	unsigned long pixel_rate, hsm_rate;
>  	int ret;
>  
> -	ret = pm_runtime_get_sync(&vc4_hdmi->pdev->dev);
> +	ret = pm_runtime_resume_and_get(&vc4_hdmi->pdev->dev);
>  	if (ret < 0) {
>  		DRM_ERROR("Failed to retain power domain: %d\n", ret);
>  		return;
> -- 
> 2.6.2
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

^ permalink raw reply	[flat|nested] 3+ messages in thread
* Re: [PATCH -next] drm: Fix PM reference leak
  2021-05-21 15:32 ` Daniel Vetter
@ 2021-05-24  6:37   ` Samuel Zou
  0 siblings, 0 replies; 3+ messages in thread
From: Samuel Zou @ 2021-05-24  6:37 UTC (permalink / raw)
  To: a.hajda, narmstrong, robert.foss, Laurent.pinchart, jonas,
	jernej.skrabec, airlied, emma, mripard, dri-devel, linux-kernel


Hi Daniel,

Thanks for your review, I will split the patch and resend.

On 2021/5/21 23:32, Daniel Vetter wrote:
> On Fri, May 21, 2021 at 09:03:06PM +0800, Zou Wei wrote:
>> pm_runtime_get_sync will increment pm usage counter even it failed.
>> Forgetting to putting operation will result in reference leak here.
>> Fix it by replacing it with pm_runtime_resume_and_get to keep usage
>> counter balanced.
>>
>> Reported-by: Hulk Robot <hulkci@huawei.com>
>> Signed-off-by: Zou Wei <zou_wei@huawei.com>
> 
> Looks good, but can you pls split this up into a patch per driver (vc and
> bridge/cdns-dsi here)?
> 
> Thanks, Daniel
> 
>> ---
>>   drivers/gpu/drm/bridge/cdns-dsi.c | 2 +-
>>   drivers/gpu/drm/vc4/vc4_hdmi.c    | 2 +-
>>   2 files changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/bridge/cdns-dsi.c b/drivers/gpu/drm/bridge/cdns-dsi.c
>> index 76373e3..b31281f 100644
>> --- a/drivers/gpu/drm/bridge/cdns-dsi.c
>> +++ b/drivers/gpu/drm/bridge/cdns-dsi.c
>> @@ -1028,7 +1028,7 @@ static ssize_t cdns_dsi_transfer(struct mipi_dsi_host *host,
>>   	struct mipi_dsi_packet packet;
>>   	int ret, i, tx_len, rx_len;
>>   
>> -	ret = pm_runtime_get_sync(host->dev);
>> +	ret = pm_runtime_resume_and_get(host->dev);
>>   	if (ret < 0)
>>   		return ret;
>>   
>> diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
>> index c27b287..f20a65b 100644
>> --- a/drivers/gpu/drm/vc4/vc4_hdmi.c
>> +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
>> @@ -798,7 +798,7 @@ static void vc4_hdmi_encoder_pre_crtc_configure(struct drm_encoder *encoder,
>>   	unsigned long pixel_rate, hsm_rate;
>>   	int ret;
>>   
>> -	ret = pm_runtime_get_sync(&vc4_hdmi->pdev->dev);
>> +	ret = pm_runtime_resume_and_get(&vc4_hdmi->pdev->dev);
>>   	if (ret < 0) {
>>   		DRM_ERROR("Failed to retain power domain: %d\n", ret);
>>   		return;
>> -- 
>> 2.6.2
>>
> 

^ permalink raw reply	[flat|nested] 3+ messages in thread
end of thread, other threads:[~2021-05-24  6:37 UTC | newest]

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2021-05-21 13:03 [PATCH -next] drm: Fix PM reference leak Zou Wei
2021-05-21 15:32 ` Daniel Vetter
2021-05-24  6:37   ` Samuel Zou

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